Abstract: A grating coupled laser (GCL) includes an active section and a passive section. The passive section is butt coupled to the active section to form a butt joint with the active section. The active section includes an active waveguide. The passive section includes a passive waveguide, a transmit grating coupler, and a top cladding. The passive waveguide is optically coupled end to end with the active waveguide and includes a first portion and a second portion. The first portion of the passive waveguide is positioned between the second portion of the passive waveguide and the active waveguide. The transmit grating coupler is optically coupled to the passive waveguide and includes grating teeth that extend upward from the second portion of the passive waveguide. The top cladding is positioned directly above the first portion of the passive waveguide and is absent directly above at least some of the transmit grating coupler.

Abstract: A grating coupled laser (GCL) includes an active section and a passive section. The passive section is butt coupled to the active section to form a butt joint with the active section. The active section includes an active waveguide. The passive section includes a passive waveguide, a transmit grating coupler, and a top cladding. The passive waveguide is optically coupled end to end with the active waveguide and includes a first portion and a second portion. The first portion of the passive waveguide is positioned between the second portion of the passive waveguide and the active waveguide. The transmit grating coupler is optically coupled to the passive waveguide and includes grating teeth that extend upward from the second portion of the passive waveguide. The top cladding is positioned directly above the first portion of the passive waveguide and is absent directly above at least some of the transmit grating coupler.

Abstract: In one example embodiment, a DFB laser includes a substrate; an active region positioned above the substrate; a grating layer positioned above the active region, the grating layer including a portion that serves as a primary etch stop layer; a secondary etch stop layer positioned above the grating layer; and a spacer layer interposed between the grating layer and the secondary etch stop layer.

Abstract: In one example embodiment, a DFB laser includes a substrate; an active region positioned above the substrate; a grating layer positioned above the active region, the grating layer including a portion that serves as a primary etch stop layer; a secondary etch stop layer positioned above the grating layer; and a spacer layer interposed between the grating layer and the secondary etch stop layer.

Abstract: In one example embodiment, a DFB laser includes a substrate, an active region positioned above the substrate, and a grating layer positioned above the active region. The grating layer includes a portion that serves as a primary etch stop layer. The DFB laser also includes a secondary etch stop layer located either above or below the grating layer, and a spacer layer interposed between the grating layer and the active region.

Abstract: Optimizing the regrowth over epitaxial layers during manufacture of a distributed feedback laser. In one example embodiment, a method for depositing an InP regrowth layer on an epitaxial base portion of a distributed feedback laser includes growing a first portion of the regrowth layer at an initial substrate temperature of approximately 580 degrees Celsius to a thickness between approximately 300 Angstroms and approximately 900 Angstroms, increasing the substrate temperature from the initial substrate temperature to an increased substrate temperature of approximately 660 degrees Celsius, growing a second portion of the regrowth layer at the increased substrate temperature, doping a first part of an uppermost layer of the regrowth layer at a concentration of approximately 8.00*10^17/cm3 at the increased substrate temperature, and doping a second part of the uppermost layer of the regrowth layer at a concentration between approximately 1.90*10^18/cm3 and approximately 2.

Abstract: In one example embodiment, a DFB laser includes a substrate, an active region positioned above the substrate, and a grating layer positioned above the active region. The grating layer includes a portion that serves as a primary etch stop layer. The DFB laser also includes a secondary etch stop layer located either above or below the grating layer, and a spacer layer interposed between the grating layer and the active region.

Abstract: Embodiments disclosed herein relate to high-speed lasers such as FP and DFB lasers. In one embodiment, the high speed laser comprises a substrate, an active region positioned above the substrate, a mesa positioned above the active region, and one or more layers disposed between the active region and the mesa, wherein the thickness of at least one of the one or more layers is implemented to at least partially minimize the distance between the mesa and active region such that lateral current spreading between the mesa and the active region is at least partially minimized.

Abstract: Semiconductor lasers having a doped active region. In one example embodiment, a laser includes a substrate and a doped active region positioned above the substrate. The doped active region includes a plurality of quantum wells separated by a plurality of barrier layers. The quantum wells and the barrier layers are doped with a doping material with a concentration between about 1*10^16/cm3 to about 1*10^17/cm3.

Abstract: This disclosure is concerned with starved source diffusion methods for forming avalanche photodiodes are provided for controlling an edge effect. In one example, a method for manufacturing an avalanche photodiode includes forming an absorber layer and an avalanche layer over a substrate. Next, a patterned mask defining one or more openings is formed over a surface of the avalanche layer. Finally, a dopant is deposited over the patterned mask and the avalanche layer such that the dopant is blocked by the patterned mask but diffuses into the avalanche layer in areas where the patterned mask defines an opening. The patterned mask is configured such that the depth to which the dopant diffuses into the avalanche layer varies so as to form a sloped diffusion front in the avalanche layer.